System of electrical distribution



(No Model.)

D. HIGHAM.

SYSTEM OF ELECTRICAL DISTRIBUTION.

No. 407,204. Patented July 16, 1.889.

WITNESSES: lNl/E/VTU/i fix ATTORNEYS,

v I Y N. PETERS. Phala-L'rtbnqmphur. wumn wmuc.

UNITED STATES PATENT OFFICE.

PENNSYLVANIA, ASSIGNOR TO THE HIGHAM PATENT RIGHT COMPANY, OF ROCKIIAND,MAINE.

SYSTEM OF ELECTRICAL DISTRIBUTION.

SPECIFICATION forming part of Letters Patent No. 407,204, dated July 16,1889.

Application filed August 17, 1888. Serial No. 283,031. (No model.)

. To all whom it may concern:

- means whereby incandescent lamps or other translating devices can besupplied from constant-current circuits of high tension without dangerto the users of the translating devices, and so that the means employedshall be selfregulating, as more fully set forth hereinafter.

The diagram in the accompanying drawing will serve to illustrate myinvention.

A A are the high-tension mains, supplied with a constant current fromgeneratingstation G. These mains may be supplied with a current of anysuitable intensity, but an ordinary arc-light circuitis preferable.Atconvenient points in this main circuit, where incandescent lamps orother translating devices are to be operated without danger to theusers, I connect in series suitable serieswound electric motors M. Inconnection with each motor I provide aseries-wound dynamo electricmachine or generator D, to be driven from the motor M by a suitableelectricallyinsulated connection. In the present instance I show a beltB, of non-conducting material, passing over pulleys (which may also beof non-conducting material) on the armature-shafts of the respectivemachines.

In the circuit E of the dynamo D, I arrange the different translatingdevices in series, from which it will be apparent that the cur-. rentset up in' the local circuit E must be one of constant intensity.

In order that the motor M and dynamo D may perform their proper functionin accordance with my invention, it will be necessary that thearmature-cores of both machines be extremely well laminated. The objectof this is to make the motor,wh en supplied with a current of constantintensity, give a practically constant pull on the belt B under any rateof speed, from the minimum to the maximum. The object of having thearmature-core of the dynamo well laminated is similar, but reversed;that is, the object is to make the dy- 5o namo, when a constant torqueis given to its armature-shaft, (by motors, for instance,) giveapractically constant current in the local circuit, whether or not thedynamo be driven at a high rate of speed to overcome the resistance of anumber of translating devices, or a slow rate of speed when workin gunder a very low resistance.

It will of course be understood, without description, that if thearmature-cores were not 6'c well laminated eddy currents would be setup, which would reduce the lift of the motor when the speed of the motoris increased, and would reduce the intensity of the current in the localcircuit when the speed of the dynamo increases.

The operation of my invention is then as follows: When current isswitched into the motor M, the armatures of both machines will instantlyrun up in speed, until a current of such intensity is set up in thelocal circuit and windings of the dynamo as to give a counter torquevery near equal to the torque of the motor. At this point the speed willrun at a fixed rate, and the current flowing through the translatingdevices in the local circuit will be held at afixed intensity. This willbe easily understood from the fact that if the current should tend torise the rotating resistance of the dynamo would increase beyond therotating effort of the motor and consequently reduce the speed, while ifthe current should tend to fall the rotating effort of the motor wouldbecome superior to the rotating resistance of the dynamo and the speedwould consequently rise, as will be readily understood without furtherdescription. Suppose, now, half the number of lamps or other devices inthe local circuit were to be out out, the current for the moment wouldof course slightly increase, and the rise in current would increase therotating resistance of the dynamo, which in turn would cause the speedto drop (very nearly one-half) until the current was normal again. Thereverse action would of course take place if an increased number oftranslating devices should be thrown into the circuit, and in this waythe machines are made selF-regulatii'ig. As the loeal circuit of each.dynamo I) is eleetrieally se 'iarated from the high -tension mains, theusers of a local circuit are in no danger from grounding of thehigh-tension mains.

My invention also possesses two incidental advantages; first as theelement of regulation is that ol' varyii'ig the speed of the armature,the cominntati r-hrushes can be set at a fixed position through thewhole Working range, for it is Well understood that the coin ditions of.non-sparking are not affected by the change of armature speed; second,the speed of. the armature is in proportion to the power consumed, and.can be easily reeordei'l by a suitable speed-recorder, thus making ameter of the utmost QCCI'UHC'Y.

In connection with the dynamo l), I n'iay use a shunt around thefield-magnetcoils with adjusialjfle resistances F, as iniflieated bydotted lines, to adjust the strength oi the fieh'l-magnet where needed.

I claim as my invention 1. The combination, with the emisl-ant-eurrentmains, ol one or moreloeal slat-ions, each containing a motor in seriesin the said. mains, a separate dynamo driven from the motor, andincandescent lamps or other translating 2. The combinationof theconstant-current mains of high-tension with one or more local stations,each eoi'ilaining a motor in series with the said mains, a separatedynamo driven from the motor through an, electrically-insulatedconnection, and ineandes ent lamps or other translating devices inseries in the lo *a[ dyname-circuit. 3. The combination olj'constant--eurrent mains of high tensionwith one or more local stations,each containing amotor in series with said mains, a separate dyna1no,ahelt for driving the latter from the motor, and incamfleseent lamps orother tra nslatine' devices in series in the local dynamo-eirouit.

In testimony whereof I have signed my name to this specification in thepresenoe of two subscribing, witnesses.

il ANIltll 'IIIHIIAM. \''itnesseslnNn v ll'ows 1N, EDWARD M. 'Rninv.

devices in series in the local dynamo circuit. 0

